Thermometer rising
CMAJ 2000;163(4):387
See response from: J.L. Sievenpiper, V. Vuksan
See also:
John Sievenpiper and colleagues recently reported significantly higher blood glucose levels at 30, 45 and 60 minutes after a 900-mL meal than after a 600-mL or 300-mL meal of 75 g of glucose [Research].1 Any increase in volume or decrease in osmolarity leading to an increase in the rate of gastric emptying during the first hour of the test with no effect on the result at 2 hours is intriguing.
There is also evidence that blood glucose levels might be affected by the ambient temperature. In Brazil, a 75-g load of glucose given to 1030 pregnant women resulted in a glucose concentration that was 0.2 mmol/L higher at 25–31°C than at 20–24°C. The corresponding value at 5–14°C was 1.03 mmol/L lower than at 25–30°C.2 This variable might affect test results in Canada given that ambient room temperature fluctuates. For the findings of Sievenpiper and collegues to be beneficial globally, comprehensive investigations should be carried out at high and low ambient temperatures.
Subhash C. Arya
Research physician
Centre for Logistical Research and Innovation
New Delhi, India
References
| 1. | Sievenpiper JL, Jenkins DJA, Josse RG, Vuksan V. Dilution of the 75-g oral glucose tolerance test increases postprandial glycemia: implications for diagnostic criteria. CMAJ 2000;162(7):993-6. |
| 2. | Schmidt MI, Matos MC, Branchtein L, Reichelt AJ, Mengue SS, Iochida LC, et al. Variation in glucose tolerance with ambient temperature. Lancet 1994;344:1054-5. [MEDLINE] |
© 2000 Canadian Medical Association or its licensors
